Sending bulk/batch data to thingspeak through SIM7600

[Husnainxi]

Hi,
Im trying to send dht22 sensor data to thingspeak server in batches. The code read and send the first batch of data successfully and prints the response code. But it does not continue reading or sending data after first batch is sent, the serial printer do not show any output, or do anything after sending first batch of data..

Please guide, to fix this issue.
CODE:

`

const char apn[] = "MY_APN";
const char gprsUser[] = "";
const char gprsPass[] = "";
const char simPIN[] = "";
const char server[] = "api.thingspeak.com";
const int port = 80;
char jsonBuffer[500] = "["; // Initialize the jsonBuffer to hold data

// TTGO T-Call pins
#define MODEM_RST 5
#define MODEM_PWKEY 4
#define MODEM_POWER_ON 23
#define MODEM_TX 27
#define MODEM_RX 26
#define SerialMon Serial
#define SerialAT Serial1
#define TIMEOUT 5000
// Configure TinyGSM library
#define TINY_GSM_MODEM_SIM7600 // Modem is SIM7600
#define TINY_GSM_RX_BUFFER 1024 // Set RX buffer to 1Kb
#include <TinyGsmClient.h>
#ifdef DUMP_AT_COMMANDS
#include <StreamDebugger.h>
StreamDebugger debugger(SerialAT, SerialMon);
TinyGsm modem(debugger);
#else
TinyGsm modem(SerialAT);
#endif
TinyGsmClient client(modem);
#define IP5306_ADDR 0x75
#define IP5306_REG_SYS_CTL0 0x00

// Sensor Libraries
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#define DHTPIN 32
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

/* Collect data once every 15 seconds and post data to ThingSpeak channel once every 2 minutes */
unsigned long lastConnectionTime = 0; // Track the last connection time
unsigned long lastUpdateTime = 0; // Track the last update time
const unsigned long postingInterval = 120L * 1000L; // Post data every 2 minutes
const unsigned long updateInterval = 15L * 1000L; // Update once every 15 seconds

void setup() {
SerialMon.begin(115200);
// Set modem reset, enable, power pins
pinMode(MODEM_PWKEY, OUTPUT);
pinMode(MODEM_RST, OUTPUT);
pinMode(MODEM_POWER_ON, OUTPUT);
digitalWrite(MODEM_PWKEY, LOW);
digitalWrite(MODEM_RST, HIGH);
digitalWrite(MODEM_POWER_ON, HIGH);
// Set GSM module baud rate and UART pins
SerialAT.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX);
delay(3000);
SerialMon.println("Initializing modem...");
modem.init();
// Configure the wake up source as timer wake up
SerialMon.print("Connecting to APN: ");
SerialMon.print(apn);
if (!modem.gprsConnect(apn, gprsUser, gprsPass)) {
SerialMon.println(" fail");
}
else {
SerialMon.println(" OK");
SerialMon.print("Connecting to ");
SerialMon.print(server);
if (!client.connect(server, port)) {
SerialMon.println(" Fail");
}
else {
SerialMon.println(" OK");
}
}
dht.begin();
}

void loop() {
// If update time has reached 1 second, then update the jsonBuffer
if (millis() - lastUpdateTime >= updateInterval) {
updatesJson(jsonBuffer);
}
}

// Updates the josnBuffer with data
void updatesJson(char* jsonBuffer) {

// Collect dht data
float t = dht.readTemperature();
float h = dht.readHumidity();
Serial.print("Temperature: "); Serial.println(t);

// Format a single data point as a JSON object
char temp[1000]; // Temporary buffer for JSON object
sprintf(temp, "{"delta_t":%lu,"field1":%.2f,"field2":%.2f},", (millis() - lastUpdateTime) / 1000, t, h);

// Append the JSON object to the jsonBuffer
strcat(jsonBuffer, temp);

// If 15 seconds have passed since the last update, send the data to ThingSpeak
if (millis() - lastConnectionTime >= postingInterval) {
// Close the JSON array
size_t len = strlen(jsonBuffer);
jsonBuffer[len - 1] = ']';

// Send data to ThingSpeak
httpRequest(jsonBuffer);

// Reset the jsonBuffer for the next batch of data
jsonBuffer[0] = '[';
jsonBuffer[1] = '\0';
}

lastUpdateTime = millis(); // Update the last update time
}

// Updates the ThingSpeakchannel with data
void httpRequest(char* jsonBuffer) {

// Format the data buffer as noted above
char data[500] = "{"write_api_key":"My_APIKEY","updates":"; // Replace YOUR-CHANNEL-WRITEAPIKEY with your ThingSpeak channel write API key
strcat(data,jsonBuffer);
strcat(data,"}");
// Close any connection before sending a new request
client.stop();
String data_length = String(strlen(data)+1); //Compute the data buffer length
Serial.println(data);
// POST data to ThingSpeak
if (client.connect(server, 80)) {
client.println("POST /channels/My_Channel_ID/bulk_update.json HTTP/1.1"); // Replace YOUR-CHANNEL-ID with your ThingSpeak channel ID
client.println("Host: api.thingspeak.com");
client.println("User-Agent: mw.doc.bulk-update (ESP8266)");
client.println("Connection: close");
client.println("Content-Type: application/json");
client.println("Content-Length: "+data_length);
client.println();
client.println(data);
String answer=getResponse();
Serial.println( answer );
}
else {
Serial.println("Failure: Failed to connect to ThingSpeak");
}
delay(250); //Wait to receive the response
client.parseFloat();
String resp = String(client.parseInt());
Serial.println("Response code:"+resp); // Print the response code. 202 indicates that the server has accepted the response
jsonBuffer[0] = '['; //Reinitialize the jsonBuffer for next batch of data
jsonBuffer[1] = '\0';
lastConnectionTime = millis(); //Update the last conenction time
}

String getResponse(){
String response;
long startTime = millis();
delay( 200 );
while ( client.available() < 1 && (( millis() - startTime ) < TIMEOUT ) ){
delay( 5 );
}
if( client.available() > 0 ){ // Get response from server.
char charIn;
do {
charIn = client.read(); // Read a char from the buffer.
response += charIn; // Append the char to the string response.
} while ( client.available() > 0 );
}
client.stop();
return response;
}`

SERIAL OUTPUT:

`17:28:25.191 -> Temperature: 26.50
17:28:40.191 -> Temperature: 26.40
17:28:55.204 -> Temperature: 26.50
17:28:55.281 -> {"write_api_key":"MY_APIKEY","updates":[{"delta_t":15,"field1":26.50,"field2":54.70},{"delta_t":15,"field1":26.60,"field2":55.10},{"delta_t":15,"field1":26.50,"field2":55.30},{"delta_t":15,"field1":26.40,"field2":55.00},{"delta_t":15,"field1":26.60,"field2":55.10},{"delta_t":15,"field1":26.50,"field2":55.30},{"delta_t":15,"field1":26.40,"field2":54.90},{"delta_t":15,"field1":26.50,"field2":55.70}]}

17:28:56.884 -> HTTP/1.1 202 Accepted
17:28:56.884 -> Date: Sat, 30 Sep 2023 09:28:57 GMT
17:28:56.884 -> Content-Type: application/json; charset=utf-8
17:28:56.884 -> Transfer-Encoding: chunked
17:28:56.884 -> Connection: close
17:28:56.884 -> Status: 202 Accepted
17:28:56.884 -> Cache-Control: no-cache
17:28:56.884 -> Access-Control-Allow-Origin: *
17:28:56.884 -> Access-Control-Max-Age: 1800
17:28:56.884 -> X-Request-Id: cbd68b65-f44b-4124-9c09-09160e202bb9
17:28:56.884 -> Access-Control-Allow-Headers: origin, content-type, X-Requested-With
17:28:56.929 -> Access-Control-Allow-Methods: GET, POST, PUT, OPTIONS, DELETE, PATCH
17:28:56.929 -> X-Frame-Options: SAMEORIGIN
17:28:56.929 ->
17:28:56.929 -> 10
17:28:56.929 -> {"success":true}
17:28:56.929 -> 0
17:28:56.929 ->
17:28:56.929 -> `